KAD44 a little rough on warmup and slight rattle noise ? With video

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aerobat

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Hello gents !

My port engine seems a little rough , it appears to slightly hunt and is shaking a bit when idling on warmup with compressor engaged . After compressor disengaging it idles like a kitty but somehow i have a tiny "rattling" noise from an unknown location .

I checked both idler pulleys and they seem to spin ok , removed the compressor belt and the clutch spins free without any noise . there is a difference to the stb engine on idle even when not severe
.

Am i chasing ghosts and its a non event or whats is your opinion ?


 
Chris_d said:
What was it?
Click to expand...

I,m still investigating but basicly plain and simple , shame on me i had not this idea .

Talked to a volvo mechanic and he told me to remove the compressor belt , fire the engine up and check if the rattling noise is gone or not .

Indeed it is and the engine now idles just fine .

So we can definitely exclude valvetrain nightmares or anything engine related , its nailed down to the compressor / compressor clutch / idler pulley .

The mechanic told me to either swap the idler pulley or just replace it , most probably its the reason . Clutch works fine and clearance is in specs so he says its the idler pulley .

Honestly i had no idea you can run a kad44 easily without the compressor belt , the engine does not care at idle .
 
I had an extremely annoying noise from my port engine (KAMD44) and even changer the supercharger compressor clutch, thinking it was that as the noise went away when the clutch disengaged. Eventually I torqued the two belt tensioners as per the Volvo spec and that sorted the issue, now no strange noises on startup.
Good luck.
 
With a torque wrench its fairly easy to set the correct belt tension , good construction by volvo !

I just ordered a new tensioner pulley , lets see if the "rattling" goes away
 
Also worth a check the top of the supercharger the sealant that volvo used to seal up the charger.
look at the bottom of page 2 here
jon and michie

Thread 'Kad 300 lagging'

Hi - I have found this weekend that the engine would get to 2500rpm easily but would take a while to get to 2900rpm never mind any higher.
I opened the hatch whilst docked and started the engine and looked at the supercharger clutch which appears to be engaging.
But I did notice at the rear of the charger where a large black pipe goes in air appeared to be coming out.
Should the connection between the charger and the pipe be air tight?
If this is the cause of the "engine lag"
Is there some sort of seal kit that is easily available.
And is it an easy fix?

An opinions welcomed
Jon

Also maybe worth changing the oil in the charger if it hasnt been done
 
I've had a similar noise on one of my KAD300s, only one engine and only when cold. After multiple attempts to get the tension right in the belt it went away when I changed the belt earlier this year. Not sure I can blame the belt - just got the tension set correctly I guess.
 
I,m next week on the boat and will change the tensioner pulley first , lets look if it changes anything .

Next point is the engine slightly "hunting" on idle with compressor engaged . Need to look at it .
 
aerobat said:
I,m still investigating but basicly plain and simple , shame on me i had not this idea .

Talked to a volvo mechanic and he told me to remove the compressor belt , fire the engine up and check if the rattling noise is gone or not .

Indeed it is and the engine now idles just fine .

So we can definitely exclude valvetrain nightmares or anything engine related , its nailed down to the compressor / compressor clutch / idler pulley .

The mechanic told me to either swap the idler pulley or just replace it , most probably its the reason . Clutch works fine and clearance is in specs so he says its the idler pulley .

Honestly i had no idea you can run a kad44 easily without the compressor belt , the engine does not care at idle .
Click to expand...
The engine only runs at idle with the compressor running until it reaches 40 degrees C then it should cut out .
 
volvopaul said:
The engine only runs at idle with the compressor running until it reaches 40 degrees C then it should cut out .
Click to expand...

thats true .

I had the "rattling" at idle after compressor disengagement at 40deg where the engine obviously still spins the compressor belt , tensioner pulley , clutch etc but does not engage the compressor anymore . After removing the compressor belt - so no more spinning the tensioner pulley and compressor clutch etc. The rattling noise is completely gone .

That tells me that the "rattling" cannot be the valvetrain of the engine but must originate somewhere from the compressor belt / tensioner pulley / compressor clutch .

Do you agree or am i missing something ?

Unfortunetly i,m not before next week on the boat to change the tensioner pulley .

Best regards
 
Believe it or not , it was just the compressor belt tensioner pulley !!!

The bearing in the old one was partially shot ( you could hear it when shaking the pulley after removal ) and on cold start with spinning the compressor ( so load on the belt / tensioner ) it must have partially sized up with the engine fighting against it it and shaking a bit . After compressor disengagement the load on the belt is reduced so the shaking was gone but the shot bearing still rattled .

New belt tensioner pulley and the engine runs like a kitty , without any rattling and not shaking anymore , with compressor engaged and disengaged !

Very happy and i give the great mechanic who told me to test the engine without the compressor belt at all more than a beer !!!
 
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